Tamsulosin is a prescription drug. It comes as a capsule you take by mouth. Tamsulosin oral capsule is available as the brand-name drug Flomax. It’s also available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in every strength or form as the brand-name drug.This drug may be used as part of a combination therapy. That means you may need to take it with other drugs.
You should not use this medication if you are allergic to tamsulosin. Do not take tamsulosin with other similar medicines such as alfuzosin (Uroxatral), doxazosin (Cardura), prazosin (Minipress), silodosin (Rapaflo), or terazosin (Hytrin).
Tamsulosin may cause dizziness or fainting, especially when you first start taking it or when you start taking it again. Be careful if you drive or do anything that requires you to be alert. Avoid standing for long periods of time or becoming overheated during exercise and in hot weather. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.
If you stop taking this medicine for any reason, call your doctor before you start taking it again. You may need a dose adjustment.
Tamsulosin can affect your pupils during cataract surgery. Tell your eye surgeon ahead of time that you are using this medication. Do not stop using tamsulosin before surgery unless your surgeon tells you to.
There are many other drugs that can interact with this medicine. Tell your doctor about all medications you use.
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
Why it’s used
Tamsulosin is used to treat the symptoms of benign prostatic hyperplasia (BPH). BPH is a condition that can occur in men. With BPH, the prostate is enlarged but isn’t cancerous.
Symptoms of BPH include trouble urinating, and a frequent or urgent need to urinate that often occurs at night.
How it works
Tamsulosin belongs to a class of drugs called alpha-adrenergic blockers. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.
Tamsulosin works by relaxing the muscles in your bladder and prostate. This helps improve the flow of your urine.
Tamsulosin oral capsule doesn’t cause drowsiness, but it can cause other side effects.
How should I take tamsulosin?
Take tamsulosin exactly as it was prescribed for you. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Tamsulosin is usually taken once a day, approximately 30 minutes after a meal. Try to take this medication at the same time each day.
Do not crush, chew, or open a capsule. Swallow the capsule whole.
Tamsulosin lowers blood pressure and may cause dizziness or fainting, especially when you first start taking it, or when you start taking it again. Call your doctor if you have severe dizziness or feel like you might pass out.
Some things can cause your blood pressure to get too low. This includes vomiting, diarrhea, heavy sweating, heart disease, dialysis, a low-salt diet, or taking diuretics (water pills). Tell your doctor if you have a prolonged illness that causes diarrhea or vomiting.
Your blood pressure will need to be checked often. You will also need to be checked for prostate cancer before and during treatment with tamsulosin.
You may feel very dizzy when you first wake up. Be careful when standing or sitting up from a lying position.
If you stop taking tamsulosin for any reason, call your doctor before you start taking it again. You may need a dose adjustment.
Store at room temperature away from moisture and heat.
Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions.
More common side effects
The more common side effects that can occur with tamsulosin include:
- runny nose
- decreased semen
- loss of energy or muscle strength
- sore throat or trouble swallowing
- back or chest pain
If these side effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.
Serious side effects
Call your doctor right away if you have serious side effects. Call 911or local emergency services if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:
- abnormal ejaculation
- priapism (painful, long-lasting erection)
- flu-like symptoms
- blurred vision
- low blood pressure that causes you to feel lightheaded, faint, or dizzy when changing positions
- allergic reaction, with trouble breathing, fever, swelling of your throat or tongue, rash, itching, or hives
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
Usual Adult Dose for:
- Benign Prostatic Hyperplasia
Additional dosage information:
- Renal Dose Adjustments
- Liver Dose Adjustments
- Dose Adjustments
- Other Comments
Usual Adult Dose for Benign Prostatic Hyperplasia
0.4 mg orally once a day; the dose may be increased to 0.8 mg orally once a day in patients who fail to respond to 0.4 mg once a day within 2 to 4 weeks
-This drug should be administered approximately one-half hour following the same meal each day.
Use: Benign prostatic hyperplasia (BPH)
Take as directed
Tamsulosin oral capsule is used for long-term treatment. It comes with risks if you don’t take it as prescribed.
If you stop taking the drug suddenly or don’t take it at all: Your BPH symptoms won’t improve. If you stop taking this drug for several days, talk to your doctor before starting again.
If you miss doses or don’t take the drug on schedule: Your medication may not work as well or may stop working completely. For this drug to work well, a certain amount needs to be in your body at all times.
If you take too much: Taking too much of this drug can cause low blood pressure. This can be dangerous.
What to do if you miss a dose: Take your dose as soon as you remember. But if you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.
How to tell if the drug is working: You should see a decrease in the symptoms of BPH. You may need to urinate less often, have less urgency to urinate, or have a stronger urine stream.
Important considerations for taking tamsulosin
Keep these considerations in mind if your doctor prescribes tamsulosin for you.
- You should take this drug 30 minutes after a meal, at the same time each day.
- Don’t crush or cut the capsule.
- Store this drug at room temperature between 59°F and 86°F (15°C and 30°C).
- Don’t freeze this medication.
- Keep this drug away from light.
- Don’t store this medication in moist or damp areas, such as bathrooms.
A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.
When traveling with your medication:
- Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
- Don’t worry about airport X-ray machines. They can’t harm your medication.
- You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled container with you.
- Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.
- Low blood pressure warning: Tamsulosin can cause you to feel dizzy or cause a drop in your blood pressure when you stand up after sitting or lying down. After taking your first dose or an increased dose, be sure you’re aware of how tamsulosin affects you before you perform any activity that could cause injury.
- Priapism warning: Rarely, tamsulosin can cause priapism. This is a persistent, painful erection that isn’t related to sexual activity. If you have priapism, contact your doctor right away. If priapism isn’t treated, it could lead to permanent impotence (not being able to have an erection).
- Skin reactions warning: Though rare, this drug can cause severe skin reactions, including a serious condition called Stevens-Johnson syndrome. These skin reactions can cause raised welts, facial swelling, fever, and trouble breathing. See a doctor right away or call 911 if you have signs of a sudden or severe skin reaction after taking this drug.
- Intraoperative floppy iris syndrome (IFIS) warning: IFIS is a complication that can occur during surgery for cataracts or glaucoma. Although rare, this problem has been reported with people taking tamsulosin. If you need to have cataract or glaucoma surgery, be sure to tell your doctor or surgeon that you’re taking tamsulosin.